From: Yinghai Lu Date: Tue, 25 Aug 2009 20:44:44 +0000 (-0700) Subject: x86: Fix vSMP boot crash X-Git-Tag: v2.6.31-rc9~38^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=295594e9cf6ae2efd73371777aa8feba0f87f42f;p=pandora-kernel.git x86: Fix vSMP boot crash 2.6.31-rc7 does not boot on vSMP systems: [ 8.501108] CPU31: Thermal monitoring enabled (TM1) [ 8.501127] CPU 31 MCA banks SHD:2 SHD:3 SHD:5 SHD:6 SHD:8 [ 8.650254] CPU31: Intel(R) Xeon(R) CPU E5540 @ 2.53GHz stepping 04 [ 8.710324] Brought up 32 CPUs [ 8.713916] Total of 32 processors activated (162314.96 BogoMIPS). [ 8.721489] ERROR: parent span is not a superset of domain->span [ 8.727686] ERROR: domain->groups does not contain CPU0 [ 8.733091] ERROR: groups don't span domain->span [ 8.737975] ERROR: domain->cpu_power not set [ 8.742416] Ravikiran Thirumalai bisected it to: | commit 2759c3287de27266e06f1f4e82cbd2d65f6a044c | x86: don't call read_apic_id if !cpu_has_apic The problem is that on vSMP systems the CPUID derived initial-APICIDs are overlapping - so we need to fall back on hard_smp_processor_id() which reads the local APIC. Both come from the hardware (influenced by firmware though) so it's a tough call which one to trust. Doing the quirk expresses the vSMP property properly and also does not affect other systems, so we go for this solution instead of a revert. Reported-and-Tested-by: Ravikiran Thirumalai Signed-off-by: Yinghai Lu Cc: Linus Torvalds Cc: Cyrill Gorcunov Cc: Shai Fultheim Cc: Suresh Siddha LKML-Reference: <4A944D3C.5030100@kernel.org> Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed